Matrix retainer



Jan. 16, 1945. Q Q s R 2,367,439

MATRIX RETAINER Filed Jan. 11, 1943 INVE OR.

24 /7 25 BY M5 50 A TTOR/VZ'MS.

Patented Jan. 16, 1945 MATRIX RETAINER Orin C. Samphere, West Allis,Wis.

Application January 11, 1943,- Serial No. 472,009

6 Claims. (01. 32-63) The present invention relates generally toimprovements in the art of dentistry, and relates more specifically toimprovements in the construction and operation of dental instruments ofthe type known to the profession as matrix retainers.

An'object of this invention is to provide an improved matrix ribbonclamp and retainer which is simple and compact in construction, andwhich is moreover highly efiicient in use.

It has long been common practice in the 'art of dentistry, to fillcavities in teeth by first properly preparing each cavity, thereaftersnugly surrounding the tooth and cavity with a flexible metallic stripknown as a matrix ribbon, then inserting the filling or impression wax,and by finally removing the matrix ribbon and finishing the filling.These matrix ribbons are highly flexible in order to cause them toreadily conform. with the contour of the teeth-embraced thereby, andwere ordinarily clamped about the selected teeth. with the aid or amatrix retainer having. a screw adjustment for producing the desiredclamping action. While these. prior matrix retainers are quite eliectivewhen applying and clamping a flexible ribbon about a cylindrical bodyhaving a recess in the side thereof, they are not well adapted to causesuch a ribbon to snugly embrace a tapered object such as a molar orbicuspid tooth; and when the ordinary matrix used on the molars whichusually taper abruptly toward'the' roots and are alsocomparativelyinaccessible for application of'thesespecial matrix strips.over could not be readily dismantled for-inspection and cleaning, andwere therefore rather unsanitary in use.

The. present invention therefore contemplates the provision of.animproved clamp and retainer whereby 'fiexible matrix ribbons orthe likemay bequickly. andefliectively applied "to even the most abruptlytapered teeth, so as to avoid. shoulders or oil-sets at the edges. offillings and to provide smooth contours for the; filled teeth- The priormatrix ribbon retainers more- Another pecific object of this inventionis to;

provide an improved matrix ribbon clampingolevice which is adapted foreither manual or auto matic adjustment so as to cause an ordinary matrixstrip to properly coact with irregular and tapered teeth at all edges oflateral relatively inaccessible cavities therein.

A further specific object of my invention is to provide a new andextremely useful and efiicient matrix retainer, which can be quicklydismantled for inspection and cleaning, and thereafter 1 readilyreassembled, and which may therefore be kept in highly sanitarycondition.

Still another specific object of theinventionr of constructing'and ofmanipulating one of the improved: matrix retainers, may be had by.refering to the drawing accompanying and form-' ing a part of thisspecification wherein like reference characters designate the same orsimilar parts inthe variousviews.

Fig. 1 is a part sectional top view of several normal teeth or a lowerjaw, showing one of the improved matrix retainers partially in section.cooperating with a matrix ribbon applied to one of the bicuspids;

Fig. 2 is an inside elevation of the assemblage of Fig; 1;

Fig. 8 is an outside elevation of the assemblage of Figs. 1 and 2; r:

Fig. 4 is an enlarged fragmentary centrallongitudinal section throughone of the improved matrix: retainers;

Fig. 5 is a similarly enlarged fragmentary in-' net side view of theribbon carrying end of the a instrument, showing the adjustable ribbonguides cially adapted to cooperate with highly flexible ways II of theframe 8 and having a rigid ribbon clamping abutment I3 at one end, andan integral wall I4 at its opposite end provided with a threaded openingI5; clamping rod I6 having one end cooperable with the slide abutment I3to firmly clamp the ends of a piece of matrix ribbon I'I thereagainst,while its opposite end is provided with a manipulating knob or handleI8, and its medial screw-threaded portion coacts with the threaded slideopening I5; an adjusting nut I9 for the slide I2, coacting with thescrew threads of the rod IS and having a reduced circular portion orannular groove 20 normally journalled in the bifurcation 2| of the framewall Ill; and a pair ofangularly adjustable ribbon guides 22, 23 whichare swingably adjustably suspended from the frame 8 near the slot 9 bymeans of pivot screws 24, 25 respectively.

The frame 8 and slide I2 may be formed of suitable sheet material,preferably metal, with the aid of punches and dies, and the oppositesides of the elongated frame 8 are provided with integral flanges26portions of which are bent inwardly toward each other to form theguideways II. The slide I2 is movable between these side flanges 26 andalong the guideways I I by the nut I9 coacting with the screw threads ofthe rod I 6 and which is journalled for rotation in the bifurcation 2|of the frame end wall Ill; and while the threaded rod I6 has screwthread coaction with the opening I5 of the slide wall I4, it has no suchscrew thread coaction with the abutment or clamping end of the slide I2but is merely freely rotatable within the opening 2! of the slide asshown in Fig. 4.

The threaded clamping and adjusting rod I8 is preferably of sufiicientlength, so that continued rotation of the ribbon tensioning nut I9 inthe proper direction, will ultimately cause the slide I2 to leave thefree end of the guideways II as in Fig. 6, whereupon the nut I9 may befreely removed from the bifurcation 2| and the rod and: slide assemblagemay be removed from the frame 8. The rod I6 may also be readily removedfrom the slide I2 and nut I9, by merely rotating the rod I6 relative tothese parts with the aid of the handle I8, thus permitting thoroughcleansing and sterilization of all parts. and the elements may obviouslybe readily reassembled in an obvious manner.

The matrix strip or flexible ribbon I7 is ordinarily formed of thinmetal and may be of any predetermined or selected length dependent uponthe size of the tooth 28 having a cavity 29 therein which is to befilled, and the ends of the ribbon pass through the opening or slot 9 inthe frame 8 and may be firmly clamped against the slide abutment I3 asillustrated in Figs. 1. and 4. The ribbon I'I passes between theadjustable guides 22, 23 and is adapted to coact with curved flanges 30formed integral with these guides so as to eliminate sharp bends; andthe two guides an elongated threaded 22, 23 are independently pivotallyadjustable about their respective retaining screws 24, 25. These screws24, 25 may be utilized to either fixedly position the guides 22, 23 inany desired angular position as shown in Fig. 5, or they may be leftloose enough so that the guides will automatically assume variousangular positions, but in either case they will by proper setting causethe loop of the ribbon I! to snugly coact with objects such as teeth 28having different tapers or contours.

The improved matrix retainer is applicable to any of the molars orbicuspids of either jaw, and has been shown applied to one of thebicuspids in Figs. 1 to 3 inclusive. During normal use of theinstrument, the dentist should first prepare the cavity 29 for receptionof the filling and should select a piece of matrix ribbon I! ofsufficient length to embrace the tooth 28 which is to be filled. Theends of the flexible ribbon I! may then be inserted through the frameslot 9 while the slide abutment I3 is disposed adjacent to this slot,and the extreme ends of the ribbon can then be firmly clamped to theabutment by rotating the clamping rod I6 within the opening I5 of thewall I4. After this clamping of the ribbon ends has been effected, thenut I9 may be rotated to move the slide I2 along the guideways I Itoward the frame end wall III and away from the opening or slot 9,thereby diminishing the size of the ribbon loop. The pivot screws 24, 25for the guides 22, 23 may then be loosened to permit pivotal swinging ofthese guides. and these screws may either be left in J loosenedcondition so as to permit automatic shifting of the guides 22, 23, orthey may be tightened after the guides have been set to conform with thetaper of the tooth 28 which is to be treated, so as to hold the ribbonguiding flanges 30 in fixed position.

The loop of the ribbon I1 may then be slipped over the tooth 28 to aposition closely adjoining the gum 3|, whereupon the nut I9 should berotated so as to shift the slide I2 away from the slot 9. Thisadjustment of the slide I2 will cause the ribbon loop to be drawn snuglyabout the tooth 28 and cavity 29, and the guide flanges 30 willeffectively cause the flexible ribbon I! to hug the tapered exterior ofthe tooth and to thoroughly seal the bottom of the cavity 29 regardlessof the shape or degree of taper of the tooth 28. The filling material orimpression wax may then be inserted within the cavit 29 and will beprevented by the ribbon II from extension beyond the tapered side of thetooth 28, and after the inserted material or wax has set. the nut I9 mayagain be manipulated to move the slide I2 awa from the frame wall I0 andtoward the slot 9, thereby releasing the ribbon tension and enlargingthe loop of the ribbon I1 sufficiently to permit free withdrawal thereoffrom the tooth 28.

After a tooth 28 has been thus filled with the aid of the improveddevice, the slide I2 may again be positioned with the abutment I3thereof over the slot 9, and the screw I 6 may be rotated relative tothe slide wall I4 and opening I5 so as to release the ribbon ends. Theused ribbon I! may then be removed, whereupon the slide I2 and rod I6together with the nut I9. may be completely removed from the frame 8 asshown in Fig.. 6, for cleaning and "sterilization. When cleansing hasbeen effected, the parts may be quickly and readily reassembled so as toplace the implement in condition for subsequent use,

and the entire manipulation is obviously very simple.

From the foregoing detailed description of the construction andoperation of the improved matrix retainer, it will be apparent that thepresent invention provides an implement which will permit rapid andeffective application of a flexible matrix ribbon to even the mostabruptly tapered teeth, in a manner which will avoid shoulders oroff-sets at the edges of the cavities and fillings. The improved matrixribbon clamping device is obviously adapted for either manual orautomatic adjustment of the guides 22, 23 so as to cause the flexiblematrix strip or ribbon H to properly coact with the irregular andtapered bodies of the teeth 28 at all edges of the cavities 29. Theimproved implement may moreover be conveniently and quickly dismantledfor cleaning purposes, and may be just as quickly reassembled forsubsequent use, and the several parts of the improved ribbon clamp andretainer ma obviously be manufactured from relatively inexpensivematerials and with the aid of simple equipment. My improved matrixretainer has proven highly satisfactory in actual use, and can bemanipulated by inexperienced persons so as to produce most effectiveresults with minimum loss of time.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode of use ofthe specific device herein shown and described, for variousmodifications within the scope of the appended claims may occur topersons skilled in the art.

I claim:

1. In combination, an elongated frame having a transverse slot, a slidemovable along said frame, a rod extending along said frame and coactingwith said slide and being adapted to clamp the ends of a flexible ribbonto the slide so as to form a tooth embracing loop adjacent to the frameand extending outwardly through said slot, adjusting means coacting withsaid rod and frame for moving said slide to vary the siz of said loop,and a pair of movable ribbon guides carried by said frame on oppositesides of said slot and coacting with the ends of the loop, said guidesbeing relatively angularly adjustable to cause said loop to assume ataper conforming with the taper of the tooth to which the loop is snuglyapplied.

2. In combination, a frame having a transverse slot, a slide movablerelative to said frame, a threaded rod coacting with said slide andbeing adapted to clamp the ends of a flexible ribbon to the slide so asto form a loop extending laterally from said frame and outwardly throughsaid slot, a nut journalled in said frame and coacting with the screwthreads of said rod to move said slide relative to said frame, andautomatically adjustable guides swingably suspended from said frame onopposite sides of said slot and coacting with the ends of the loop tocause said loop to assume a definite laterally tapered formation whenthe same is drawn into snug engagement with a tapered tooth.

3. In combination, a frame having a transverse slot, means carried bysaid frame and being adapted to clamp the ends of a piece of flexibleribbon to form a tooth embracing loop disposed near an end of the frameand extending outwardly through said slot, adjusting means coacting withsaid frame to vary the size of said loop, and a pair of spaced andfreely relatively angularly adjustable guides carried by said frame onopposite sides of said slot and coacting with said ribbon between itsclamped ends and said loop for causing the ribbon loop to assume adefinite laterally tapered formation when the loop is drawn into snugembracing engagement with a tapered tooth.

4; In combination, an elongated frame having .tooth to which the loop issnugly applied.

5. In combination, an elongated frame having a transverse slot near oneend and guideways extending away from'said slot, a slide movable alongsaid guideways, a rod coacting with said slide and being operable toclamp a flexible ribbon to the slide so as to form a loop extendingoutwardly through said slot, means coacting with said frame and rod tomove said slide along said guideways away from said slot and to therebydiminish said loop, and a guide swingably suspended from said frame oneach side of said slot and coacting with the adjacent end of the loop,

' said guides being relatively angularly displaceable to cause the loopto assume the taper of the tooth about which the loop is snugly drawnwhen said slide is moved away from said slot,

6. In combination, a frame having a transverse slot, a slidemovable'along said frame, a rod coacting with said frame and slide tomove the latter relative to said slot, means for fastening a matrixribbon to said rod and slide to form a loop extending outwardly throughsaid slot, means for moving said rod to diminish the size of said loop,and a guide pivotally attached to said frame on each side of said slotand coacting with the adjacent end of the loop, said guides beingrelatively angularly displaceable to caus the loop ribbon to snuglyembrace teeth of diverse tapered formations.

ORIN C. SAMPHERE.

